Fuel Economy Calculator
Convert L/100km ↔ US/UK MPG, or estimate trip fuel from distance and consumption.
Input Data
Results
At a glance:L/100km is litres per 100 km (lower is more efficient); MPG is miles per gallon (higher is better). Conversion: MPG (US) = 235.214583 ÷ L/100km; MPG (UK) = 282.480936 ÷ L/100km (1 US gal = 3.785411784 L, 1 UK gal = 4.54609 L). Trip: fuel (L) = distance (km) × L/100km ÷ 100.
Formula
MPG (US) = 235.214583 ÷ (L/100km); MPG (UK) = 282.480936 ÷ (L/100km).
fuel (L) = distance × consumption ÷ 100.
How to Use
- convert: enter value and pick from/to unit.
- trip: enter distance and consumption to get required fuel.
Case Studies
8 L/100km → mpg (US)
235.2146 ÷ 8 ≈ 29.40 mpg (US).
300 km @ 8 L/100km
fuel = 300 × 8 ÷ 100 = 24 L.
FAQ
L/100km vs MPG?
Europe/Asia use L/100km (lower is better); the US uses MPG (higher is better). They are reciprocals.
US vs UK MPG?
Different gallons: US gal = 3.785 L, UK gal = 4.546 L, so the same fuel shows a larger number in UK MPG.
Lower is better?
L/100km lower means more fuel-efficient. Hybrids often < 5; large SUVs may exceed 12.
Real vs rated consumption?
Real-world use (traffic, load, climate) is often 10–20% higher than the factory figure.
Cost estimate?
fuel × price = cost. Pair with the fuel-price calculator.
Precision?
Shown to 4 decimals; coefficients are exact.
Related Tools
References
Content review: Calculatorism Lifestyle Team. Results are for reference only; please refer to the relevant authorities for the official figures.